Reducing resonance peaks and drive tones from a micro-electro-mechanical system gyroscope response

ABSTRACT

Reducing noise from drive tone and sense resonance peaks of a micro-electro-mechanical system (MEMS) gyroscope output using a notch filter is presented herein. The MEMS gyroscope can include a drive oscillation component configured to vibrate a sensor mass at a drive resonance frequency; a sense circuit configured to detect a deflection of the sensor mass, and generate, based on the deflection and the drive resonance frequency, a demodulated output; and a signal processing component configured to receive a set of frequencies comprising a first value representing the drive resonance frequency and a second value corresponding to a sense resonance frequency associated with the sense circuit, and apply, based on the first value and the second value, a notch filter to the demodulated output to obtain a filtered output.

TECHNICAL FIELD

The subject disclosure generally relates to embodiments for reducingresonance peaks and drive tones from a micro-electro-mechanical system(MEMS) gyroscope response.

BACKGROUND

Processing of a Coriolis based output response of a MEMS gyroscopeproduces drive tone and resonance peaks at a difference between driveand sense resonant frequencies of the MEMS gyroscope. Althoughconventional MEMS gyroscope technologies utilize a low pass filter toreduce noise from drive tone and sense resonance peaks, suchtechnologies increase filter settling time and system latency—negativelyimpacting system stability. In this regard, conventional MEMS gyroscopetechnologies have had some drawbacks, some of which may be noted withreference to the various embodiments described herein below.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting embodiments of the subject disclosure are described withreference to the following figures, wherein like reference numeralsrefer to like parts throughout the various views unless otherwisespecified:

FIG. 1 illustrates a block diagram of a MEMS gyroscope including asignal processing component, in accordance with various embodiments;

FIG. 2 illustrates a block diagram of a drive oscillation component of aMEMS gyroscope, in accordance with various embodiments;

FIG. 3 illustrates another block diagram of a MEMS gyroscope, inaccordance with various embodiments;

FIG. 4 illustrates a waveform of a MEMS sense resonance frequencyresponse;

FIG. 5 illustrates a waveform of a transfer function corresponding to afrequency response of a MEMS gyroscope, in accordance with variousembodiments;

FIG. 6 illustrates another waveform of a transfer function correspondingto a frequency response of a MEMS gyroscope, in accordance with variousembodiments;

FIG. 7 illustrates a waveform of a frequency responses of a MEMSgyroscope, in accordance with various embodiments;

FIG. 8 illustrates a block diagram of a MEMS gyroscope configurationsystem, in accordance with various embodiments;

FIG. 9 illustrates a flowchart of a method associated with a MEMSgyroscope, in accordance with various embodiments;

FIG. 10 illustrates a flow chart a method associated with a system forconfiguration of a MEMS gyroscope, in accordance with variousembodiments; and

FIG. 11 illustrates a block diagram representing an illustrativenon-limiting computing system or operating environment in which one ormore aspects of various embodiments described herein can be implemented.

DETAILED DESCRIPTION

Aspects of the subject disclosure will now be described more fullyhereinafter with reference to the accompanying drawings in which exampleembodiments are shown. In the following description, for purposes ofexplanation, numerous specific details are set forth in order to providea thorough understanding of the various embodiments. However, thesubject disclosure may be embodied in many different forms and shouldnot be construed as limited to the example embodiments set forth herein.

As described above, conventional MEMS gyroscope technologies have hadsome drawbacks with respect to use of a low pass filter to reduce noisefrom drive tone and sense resonance peaks. Various embodiments disclosedherein can improve system stability by utilizing a programmable notchfilter to “notch out” frequencies corresponding to such peaks.

For example, a MEMS gyroscope can comprise a drive oscillation componentthat can be configured to vibrate a sensor mass at a drive resonancefrequency, e.g., corresponding to a resonant frequency of the sensormass. In an embodiment, the drive oscillation component can beconfigured to generate mechanical resonance of the sensor mass at thedrive resonance frequency.

The MEMS gyroscope can further comprise a sense circuit that can beconfigured to detect a deflection, displacement, etc. of the sensormass, e.g., corresponding to a coriolis force applied to the MEMSgyroscope, and generate, based on the deflection and the drive resonancefrequency, a demodulated output. In one embodiment, the sense circuitcan be configured to determine a change in capacitance of sensorscapacitively coupled to the sensor mass.

In another embodiment, the sense circuit can be configured to generate,based on the change in the capacitance of the sensors, a deflectionoutput, and amplify the deflection output using a charge-to-voltageamplifier to obtain an amplified output corresponding to the coriolisforce, e.g., modulated by the drive resonance frequency. The sensecircuit can be configured to demodulate, based on the drive resonancefrequency, the amplified output to obtain a demodulated output—thedemodulated output comprising resonant peaks at a difference between thedrive resonance frequency and a sense resonance frequency correspondingto the sensors, and at integer multiples, or tones, of the driveresonance frequency.

In this regard, the MEMS gyroscope can further comprise a signalprocessing component that can be configured to receive a set offrequencies comprising a first value representing the drive resonancefrequency and a second value corresponding to the sense resonancefrequency. Further, the signal processing component can be configured toapply, based on the first value and the second value, a notch filter tothe demodulated output to obtain a filtered output.

In one embodiment, the sense circuit can be configured to convert thedemodulated output to a digital value utilizing an analog-to-digitalconverter. In this regard, the signal processing component can beconfigured to apply the notch filter to the digital value, e.g.,utilizing a digital filter, to obtain the filtered output.

In another embodiment, the signal processing component can be configuredto apply a low pass filter to the filtered output, e.g., the low passfilter having a cut-off frequency that is higher than cut-offfrequencies of low pass filters of conventional MEMS gyroscopetechnologies.

In an embodiment, a method can comprise vibrating, by a driveoscillation component of a MEMS gyroscope, a sensor mass of the MEMSgyroscope at a drive resonance frequency, e.g., corresponding to aresonant frequency of the sensor mass. In one embodiment, the vibratingof the sensor mass can comprise generating, by the drive oscillationcomponent, mechanical resonance of the sensor mass at the driveresonance frequency.

Further, the method can comprise detecting, by a sense circuit of theMEMS gyroscope, a deflection, displacement, etc. of the sensor mass,e.g., corresponding to a coriolis force applied to the MEMS gyroscope,and generating, by the sense circuit based on the deflection and thedrive resonance frequency, a demodulated output. In an embodiment, thedetecting of the deflection, displacement, etc. can comprise determininga change in capacitance of sensors capacitively coupled to the sensormass.

In another embodiment, the generating of the demodulated output cancomprise amplifying a deflection output representing the change incapacitance using a charge-to-voltage amplifier to obtain an amplifiedoutput, and demodulating, based on the drive resonance frequency, theamplified output to obtain the demodulated output. In yet anotherembodiment, the generating of the demodulated output can compriseconverting the demodulated output to a digital value utilizing ananalog-to-digital converter.

Further, the method can include receiving, by a signal processingcomponent of the MEMS gyroscope, a set of frequencies from a memory—theset of frequencies comprising a first value representing the driveresonance frequency and a second value corresponding to a senseresonance frequency associated with the sense circuit. Furthermore, themethod can include applying, by the signal processing component based onthe first value and the second value, a notch filter to the demodulatedoutput to obtain a filtered output. In an embodiment, the applying ofthe notch filter can comprise applying the notch filter to the digitalvalue to obtain the filtered output. In one embodiment, the method cancomprise applying, by the signal processing component, a low pass filterto the filtered output.

In another embodiment, a system can comprise a frequency identificationcomponent that can be configured to determine a drive resonancefrequency corresponding to a vibration of a sensor mass of a MEMSgyroscope, and determine a sense resonance frequency of a sense circuitof the MEMS gyroscope. Further, the system can comprise a programmingcomponent that can be configured to store the drive resonance frequencyand a value corresponding to the sense resonance frequency in a memoryto facilitate an application, by the MEMS gyroscope, of a notch filterto a demodulated output using the drive resonance frequency and thevalue corresponding to the sense resonance frequency—the demodulatedoutput corresponding to a coriolis force associated with a deflection ofthe sensor mass. In an embodiment, the value corresponding to the senseresonance frequency represents the sense resonance frequency and/or adifference between the sense resonance frequency and the drive resonancefrequency.

In yet another embodiment, the frequency identification component can beconfigured to determine drive resonance frequencies corresponding tosensor masses of respective axes, e.g., x, y, and z, of the MEMSgyroscope, and determine sense resonance frequencies associated withsensors of the sensor masses. In this regard, the programming componentcan be configured to store the drive resonance frequencies correspondingto the sensor masses of the respective axes of the MEMS gyroscope, andvalues corresponding to the sense resonance frequencies associated withthe sensors of the sensor masses, in the memory to facilitate a use, bythe MEMS gyroscope, of notch filters according to the drive resonancefrequencies and the values corresponding to the sense resonancefrequencies.

Reference throughout this specification to “one embodiment,” or “anembodiment,” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment,” or “in an embodiment,” in various places throughout thisspecification are not necessarily all referring to the same embodiment.Furthermore, the particular features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments.

Furthermore, to the extent that the terms “includes,” “has,” “contains,”and other similar words are used in either the detailed description orthe appended claims, such terms are intended to be inclusive—in a mannersimilar to the term “comprising” as an open transition word—withoutprecluding any additional or other elements. Moreover, the term “or” isintended to mean an inclusive “or” rather than an exclusive “or”. Thatis, unless specified otherwise, or clear from context, “X employs A orB” is intended to mean any of the natural inclusive permutations. Thatis, if X employs A; X employs B; or X employs both A and B, then “Xemploys A or B” is satisfied under any of the foregoing instances. Inaddition, the articles “a” and “an” as used in this application and theappended claims should generally be construed to mean “one or more”unless specified otherwise or clear from context to be directed to asingular form.

Aspects of apparatus, devices, systems, processes, and process blocksexplained herein can constitute machine-executable instructions embodiedwithin a machine, e.g., embodied in a memory device, computer readablemedium (or media) associated with the machine. Such instructions, whenexecuted by the machine, can cause the machine to perform the operationsdescribed. Additionally, aspects of the apparatus, devices, systems,processes, and process blocks can be embodied within hardware, such asan application specific integrated circuit (ASIC) or the like. Moreover,the order in which some or all of the process blocks appear in eachprocess should not be deemed limiting. Rather, it should be understoodby a person of ordinary skill in the art having the benefit of theinstant disclosure that some of the process blocks can be executed in avariety of orders not illustrated.

Furthermore, the word “exemplary” and/or “demonstrative” is used hereinto mean serving as an example, instance, or illustration. For theavoidance of doubt, the subject matter disclosed herein is not limitedby such examples. In addition, any aspect or design described herein as“exemplary” and/or “demonstrative” is not necessarily to be construed aspreferred or advantageous over other aspects or designs, nor is it meantto preclude equivalent exemplary structures and techniques known tothose of ordinary skill in the art having the benefit of the instantdisclosure.

Conventional MEMS gyroscope technologies have had some drawbacks withrespect to use of a low pass filter to reduce noise from drive tone andsense resonance peaks. On the other hand, various embodiments disclosedherein can improve system stability by utilizing a programmable notchfilter to “notch out” frequencies corresponding to such peaks.

In this regard, and now referring to FIG. 1, MEMS gyroscope 101 includesdrive oscillation component 110, sense circuit 120, and signalprocessing component 130. Drive oscillation component 110 can vibratesensor mass 115 at a drive resonance frequency, e.g., corresponding to aresonant frequency of sensor mass 115. As illustrated by FIGS. 2 and 3,drive oscillation component 110 includes MEMS drive resonance circuit210 and feedback circuit 220. Feedback circuit 220 includescharge-to-voltage voltage amplifier 322 that generates a clock signalbased on a change in capacitance corresponding to a movement, oroscillation, of sensor mass 115, e.g., of MEMS die 310. In this regard,amplitude control component 324 can modify the gain of phaseshifter-drive buffer 326 to maintain, via MEMS drive resonance circuit210 of MEMS die 310, a mechanical resonance of sensor mass 115, at thedrive resonance frequency and a substantially constant amplitude.

Sense circuit 120 can detect a deflection, displacement, etc. of sensormass 115, e.g., corresponding to a coriolis force applied to MEMSgyroscope 101. In one embodiment, sense circuit 120 can detect thedeflection, displacement, etc. of sensor mass 115 by determining achange in capacitance of sensors 125 capacitively coupled to sensor mass115. As illustrated by FIG. 3, MEMS die 310 can generate, based on thechange in capacitance of sensors 125, a deflection output. Further,charge-to-voltage amplifier 320 can amplify the deflection output toobtain an amplified output corresponding to the coriolis force, e.g.,modulated by the drive resonance frequency. As illustrated by FIG. 4,waveform 400 of a sense resonance frequency response of MEMS gyroscope101 comprises an amplitude response peak at F_(sense), or the senseresonance frequency. Further, waveform 400 comprises a differentamplitude response magnitude at F_(drive), or the drive resonancefrequency.

Based on the deflection and the drive resonance frequency, sense circuit120 can generate a demodulated output. In this regard, phase-locked-loop(PLL) 330 can receive, from a comparator with hysteresis, e.g., Schmitttrigger 328, a clock signal that oscillates at the drive resonancefrequency. Demodulator 340 can receive a clock signal from PLL 330corresponding to the drive resonance frequency and demodulate, based onthe clock signal, the amplified output corresponding to the coriolisforce to obtain a demodulated output.

FIG. 5 illustrates waveform 500 of a transfer function corresponding tothe demodulated output. Waveform 500 comprises a peak at|F_(sense)−F_(drive)|, with the peak magnitude diminished by ratio|F_(sense)−F_(drive)|/F_(sense). The peak amplifies MEMS Brownian noiseand contributes significantly to total system noise, unless filtered. Asillustrated by FIG. 6, waveform 600 of the transfer function furtherincludes tones at integer multiples of F_(drive), or the drive resonancefrequency. Such tones can also contribute to total system noise.

In this regard, signal processing component 130 can receive, e.g., froma processing device coupled to MEMS gyroscope 101, e.g., from system 810(see below), a set of frequencies comprising a first value representingthe drive resonance frequency and a second value corresponding to thesense resonance frequency, e.g., the second value representing adifference between the drive resonance frequency and the sense resonancefrequency. Further, signal processing component 130 can apply, based onthe first value and the second value, a notch filter to the demodulatedoutput to obtain a filtered output. In an embodiment, the second valuecorresponding to the sense resonance frequency represents the senseresonance frequency. In another embodiment, the second value representsa difference between the sense resonance frequency and the driveresonance frequency.

In one embodiment, sense circuit 120 can convert the demodulated outputto a digital value utilizing analog-to-digital converter 350. In thisregard, signal processing component 130 can apply the notch filter tothe digital value, e.g., utilizing a digital filter, to obtain thefiltered output. As illustrated by FIG. 7, signal processing component130 can place notches, or “zeros”, at |F_(sense)−F_(drive)| andfrequency locations associated with tones, or integer multiples, ofF_(drive), utilizing the digital filter, e.g., a programmable filter,etc. In this regard, use of the notch filter to reduce sense resonancepeak and drive tone noise can significantly lower system latency, andimprove performance in certain closed loop applications, e.g.,associated with optical image stabilization.

In another embodiment, signal processing component 130 can apply a lowpass filter (not shown) to the filtered output, e.g., the low passfilter having a cut-off frequency that is higher than cut-offfrequencies of low pass filters of conventional MEMS gyroscopetechnologies.

It should be appreciated that portions of drive oscillation component110 and sense circuit 120 that are not included in MEMS die 310 can beincluded in a separate die, chip, ASIC, etc. In this regard, PLL 330 andsignal processing component 130 can be included in the separate die,chip, ASIC, etc.

FIG. 8 illustrates a block diagram (800) of a MEMS gyroscopeconfiguration system (810), in accordance with various embodiments. MEMSgyroscope configuration system 810 includes frequency identificationcomponent 820, programming component 830, and memory 840. Frequencyidentification component 820 can determine a drive resonance frequencycorresponding to a vibration of sensor mass 115 of MEMS gyroscope 101.Further, frequency identification component 820 can determine a senseresonance frequency of sensors 125 of MEMS gyroscope 101.

Programming component 830 can store the drive resonance frequency and avalue corresponding to the sense resonance frequency in memory 840 tofacilitate an application, by MEMS gyroscope 101 using the driveresonance frequency and the value corresponding to the sense resonancefrequency, of a notch filter to a demodulated output corresponding to acoriolis force associated with a deflection of sensor mass 115 of MEMSgyroscope 101. In an embodiment, the value corresponding to the senseresonance frequency represents the sense resonance frequency and/or adifference between the sense resonance frequency and the drive resonancefrequency. It should be appreciated that in other embodiments (notshown), memory 840 can be separate from system 810, included in MEMSgyroscope 101, etc.

In another embodiment, frequency identification component 820 candetermine drive resonance frequencies corresponding to sensor masses(e.g., 115) of respective axes, e.g., x, y, and z, of MEMS gyroscope101, and determine sense resonance frequencies associated with sensors(e.g., 125) of the sensor masses. In this regard, an analog multiplexer(not shown) can be included in drive oscillation component 110 of MEMSgyroscope 101 to provide output signals of the respective axes tocharge-to-voltage amplifier 322, and/or provide feedback signals fromphase shifter-drive buffer 326 to the sensor masses of the respectiveaxes. Further, other analog multiplexers (not shown) can be included insense circuit 120 of MEMS gyroscope 101 to provide output signals fromthe sensors of the sensor masses of the respective axes tocharge-to-voltage amplifier 320.

Programming component 830 can be configured to store the drive resonancefrequencies corresponding to the sensor masses of the respective axes ofthe MEMS gyroscope, and values corresponding to the sense resonancefrequencies associated with the sensors of the sensor masses, in memory840 to facilitate a use, by MEMS gyroscope 101, of notch filter(s)according to the drive resonance frequencies and the valuescorresponding to the sense resonance frequencies.

FIGS. 9-10 illustrate methodologies in accordance with the disclosedsubject matter. For simplicity of explanation, the methodologies aredepicted and described as a series of acts. It is to be understood andappreciated that various embodiments disclosed herein are not limited bythe acts illustrated and/or by the order of acts. For example, acts canoccur in various orders and/or concurrently, and with other acts notpresented or described herein. Furthermore, not all illustrated acts maybe required to implement the methodologies in accordance with thedisclosed subject matter. In addition, those skilled in the art willunderstand and appreciate that the methodologies could alternatively berepresented as a series of interrelated states via a state diagram orevents. Additionally, it should be further appreciated thatmethodologies disclosed hereinafter and throughout this specificationare capable of being stored on an article of manufacture to facilitatetransporting and transferring such methodologies to computers,processors, processing components, etc. The term article of manufacture,as used herein, is intended to encompass a computer program accessiblefrom any computer-readable device, carrier, or media.

Referring now to FIG. 9, process 900 performed by a MEMS gyroscope (e.g.101) is illustrated, in accordance with various embodiments. At 910, asensor mass of the MEMS gyroscope can be vibrated by a drive oscillationcomponent of the MEMS gyroscope at a drive resonance frequency, e.g.,corresponding to a resonant frequency of the sensor mass. At 920, adeflection, displacement, etc. of the sensor mass, e.g., correspondingto a coriolis force that has been applied to the MEMS gyroscope, can bedetected by a sense circuit of the MEMS gyroscope, e.g., based on adetermined change in capacitance of sensors capacitively coupled to thesensor mass.

At 930, a demodulated output can be generated by the sense circuit basedon the deflection and the drive resonance frequency. In one embodiment(not shown), a deflection output representing the change in capacitanceof the sensors can be amplified by the sense circuit, e.g., using acharge-to-voltage amplifier, to obtain an amplified output, and theamplified output can be demodulated by the sense circuit, based on thedrive resonance frequency, to obtain the demodulated output. In anotherembodiment, (not shown), the demodulated output can be converted by thesense circuit to a digital value using an analog-to-digital converter.

At 940, a set of frequencies comprising a first value representing thedrive resonance frequency and a second value corresponding to a senseresonance frequency associated with the sense circuit can be received,e.g., from system 810, by a signal processing component of the MEMSgyroscope. In an embodiment, the second value can represent a differencebetween the drive resonance frequency and the sense resonance frequency.At 950, a notch filter can be applied, by the signal processingcomponent based on the first value and the second value, to thedemodulated output, the digital value, etc. to obtain a filtered output.

FIG. 10 illustrates a process (1000) performed by a system (e.g. 810),in accordance with various embodiments. At 1010, a drive resonancefrequency corresponding to a vibration of a sensor mass of a MEMSgyroscope, e.g., MEMS gyroscope 101, can be determined by a frequencyidentification component of the system. At 1020, a sense resonancefrequency of a sense circuit of the MEMS gyroscope can be determined bythe frequency identification component. At 1030, the drive resonancefrequency and a value corresponding to the sense resonance frequency canbe stored, by a programming component of the system, in a memory tofacilitate an application, by the MEMS gyroscope using the driveresonance frequency and the value, of a notch filter to a demodulatedoutput corresponding to a coriolis force associated with a deflection ofthe sensor mass of the MEMS gyroscope. In an embodiment, the valuecorresponding to the sense resonance frequency represents the senseresonance frequency and/or a difference between the sense resonancefrequency and the drive resonance frequency.

In another embodiment (not shown), drive resonance frequenciescorresponding to sensor masses of axes of the MEMS gyroscope, and senseresonance frequencies of sensors corresponding to the sensor masses canbe determined by the frequency identification component. Further, thedrive resonance frequencies and values corresponding to the senseresonance frequencies can be stored, by the programming component, inthe memory to facilitate use, by the MEMS gyroscope, of notch filtersaccording to the drive resonance frequencies and the valuescorresponding to the sense resonance frequencies.

As it employed in the subject specification, the terms “processor”,“processing component”, etc. can refer to substantially any computingprocessing unit or device, e.g., MEMS gyroscope 101, system 810, etc.comprising, but not limited to comprising, single-core processors;single-processors with software multithread execution capability;multi-core processors; multi-core processors with software multithreadexecution capability; multi-core processors with hardware multithreadtechnology; parallel platforms; and parallel platforms with distributedshared memory. Additionally, a processor can refer to an integratedcircuit, an ASIC, a digital signal processor (DSP), a field programmablegate array (FPGA), a programmable logic controller (PLC), a complexprogrammable logic device (CPLD), a discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions and/or processes described herein. Further, aprocessor can exploit nano-scale architectures such as, but not limitedto, molecular and quantum-dot based transistors, switches and gates,e.g., in order to optimize space usage or enhance performance of mobiledevices. A processor can also be implemented as a combination ofcomputing processing units, devices, etc.

In the subject specification, terms such as “memory” and substantiallyany other information storage component, e.g., memory 840, relevant tooperation and functionality of systems and/or devices disclosed herein,e.g., MEMS gyroscope 101, system 810, etc. refer to “memory components,”or entities embodied in a “memory,” or components comprising the memory.It will be appreciated that the memory can include volatile memoryand/or nonvolatile memory. By way of illustration, and not limitation,volatile memory, can include random access memory (RAM), which can actas external cache memory. By way of illustration and not limitation, RAMcan include synchronous RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM(SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM),Synchlink DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct Rambusdynamic RAM (DRDRAM), and/or Rambus dynamic RAM. In other embodiment(s)nonvolatile memory can include read only memory (ROM), programmable ROM(PROM), electrically programmable ROM (EPROM), electrically erasable ROM(EEPROM), or flash memory. Additionally, the MEMS microphones and/ordevices disclosed herein can comprise, without being limited tocomprising, these and any other suitable types of memory.

In order to provide a context for the various aspects of the disclosedsubject matter, FIG. 11, and the following discussion, are intended toprovide a brief, general description of a suitable environment in whichthe various aspects of the disclosed subject matter, e.g., correspondingto system 810, can be implemented. While the subject matter has beendescribed above in the general context of computer-executableinstructions of a computer program that runs on a computer and/orcomputers, those skilled in the art will recognize that variousembodiments disclosed herein can be implemented in combination withother program modules. Generally, program modules comprise routines,programs, components, data structures, etc. that perform particulartasks and/or implement particular abstract data types.

Moreover, those skilled in the art will appreciate that the inventivesystems can be practiced with other computer system configurations,comprising single-processor or multiprocessor computer systems,computing devices, mini-computing devices, mainframe computers, as wellas personal computers, hand-held computing devices (e.g., PDA, phone,watch), microprocessor-based or programmable consumer or industrialelectronics, and the like. The illustrated aspects can also be practicedin distributed computing environments where tasks are performed byremote processing devices that are linked through a communicationnetwork; however, some if not all aspects of the subject disclosure canbe practiced on stand-alone computers. In a distributed computingenvironment, program modules can be located in both local and remotememory storage devices.

With reference to FIG. 11, a block diagram of a computing system 1100operable to execute the disclosed systems and methods, e.g.,corresponding to system 810, is illustrated, in accordance with anembodiment. Computer 1112 comprises a processing unit 1114, a systemmemory 1116, and a system bus 1118. System bus 1118 couples systemcomponents comprising, but not limited to, system memory 1116 toprocessing unit 1114. Processing unit 1114 can be any of variousavailable processors. Dual microprocessors and other multiprocessorarchitectures also can be employed as processing unit 1114.

System bus 1118 can be any of several types of bus structure(s)comprising a memory bus or a memory controller, a peripheral bus or anexternal bus, and/or a local bus using any variety of available busarchitectures comprising, but not limited to, industrial standardarchitecture (ISA), micro-channel architecture (MSA), extended ISA(EISA), intelligent drive electronics (IDE), VESA local bus (VLB),peripheral component interconnect (PCI), card bus, universal serial bus(USB), advanced graphics port (AGP), personal computer memory cardinternational association bus (PCMCIA), Firewire (IEEE 1394), smallcomputer systems interface (SCSI), and/or controller area network (CAN)bus used in vehicles.

System memory 1116 comprises volatile memory 1120 and nonvolatile memory1122. A basic input/output system (BIOS), containing routines totransfer information between elements within computer 1112, such asduring start-up, can be stored in nonvolatile memory 1122. By way ofillustration, and not limitation, nonvolatile memory 1122 can compriseROM, PROM, EPROM, EEPROM, or flash memory. Volatile memory 1120comprises RAM, which acts as external cache memory. By way ofillustration and not limitation, RAM is available in many forms such asSRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, RDRAM, DRDRAM, and Rambusdynamic RAM.

Computer 1112 also comprises removable/non-removable,volatile/non-volatile computer storage media. FIG. 11 illustrates, forexample, disk storage 1124. Disk storage 1124 comprises, but is notlimited to, devices like a magnetic disk drive, floppy disk drive, tapedrive, Jaz drive, Zip drive, LS-100 drive, flash memory card, or memorystick. In addition, disk storage 1124 can comprise storage mediaseparately or in combination with other storage media comprising, butnot limited to, an optical disk drive such as a compact disk ROM device(CD-ROM), CD recordable drive (CD-R Drive), CD rewritable drive (CD-RWDrive) or a digital versatile disk ROM drive (DVD-ROM). To facilitateconnection of the disk storage devices 1124 to system bus 1118, aremovable or non-removable interface is typically used, such asinterface 1126.

It is to be appreciated that FIG. 11 describes software that acts as anintermediary between users and computer resources described in suitableoperating environment 1100. Such software comprises an operating system1128. Operating system 1128, which can be stored on disk storage 1124,acts to control and allocate resources of computer system 1112. Systemapplications 1130 take advantage of the management of resources byoperating system 1128 through program modules 1132 and program data 1134stored either in system memory 1116 or on disk storage 1124. It is to beappreciated that the disclosed subject matter can be implemented withvarious operating systems or combinations of operating systems.

A user can enter commands or information into computer 1112 throughinput device(s) 1136. Input devices 1136 comprise, but are not limitedto, a pointing device such as a mouse, trackball, stylus, touch pad,keyboard, microphone, joystick, game pad, satellite dish, scanner, TVtuner card, digital camera, digital video camera, web camera, cellularphone, user equipment, smartphone, and the like. These and other inputdevices connect to processing unit 1114 through system bus 1118 viainterface port(s) 1138. Interface port(s) 1138 comprise, for example, aserial port, a parallel port, a game port, a universal serial bus (USB),a wireless based port, e.g., Wi-Fi, Bluetooth, etc. Output device(s)1140 use some of the same type of ports as input device(s) 1136.

Thus, for example, a USB port can be used to provide input to computer1112 and to output information from computer 1112 to an output device1140. Output adapter 1142 is provided to illustrate that there are someoutput devices 1140, like display devices, light projection devices,monitors, speakers, and printers, among other output devices 1140, whichuse special adapters. Output adapters 1142 comprise, by way ofillustration and not limitation, video and sound devices, cards, etc.that provide means of connection between output device 1140 and systembus 1118. It should be noted that other devices and/or systems ofdevices provide both input and output capabilities such as remotecomputer(s) 1144.

Computer 1112 can operate in a networked environment using logicalconnections to one or more remote computers, such as remote computer(s)1144. Remote computer(s) 1144 can be a personal computer, a server, arouter, a network PC, a workstation, a microprocessor based appliance, apeer device, or other common network node and the like, and typicallycomprises many or all of the elements described relative to computer1112.

For purposes of brevity, only a memory storage device 1146 isillustrated with remote computer(s) 1144. Remote computer(s) 1144 islogically connected to computer 1112 through a network interface 1148and then physically and/or wirelessly connected via communicationconnection 1150. Network interface 1148 encompasses wire and/or wirelesscommunication networks such as local-area networks (LAN) and wide-areanetworks (WAN). LAN technologies comprise fiber distributed datainterface (FDDI), copper distributed data interface (CDDI), Ethernet,token ring and the like. WAN technologies comprise, but are not limitedto, point-to-point links, circuit switching networks like integratedservices digital networks (ISDN) and variations thereon, packetswitching networks, and digital subscriber lines (DSL).

Communication connection(s) 1150 refer(s) to hardware/software employedto connect network interface 1148 to bus 1118. While communicationconnection 1150 is shown for illustrative clarity inside computer 1112,it can also be external to computer 1112. The hardware/software forconnection to network interface 1148 can comprise, for example, internaland external technologies such as modems, comprising regular telephonegrade modems, cable modems and DSL modems, wireless modems, ISDNadapters, and Ethernet cards.

The computer 1112 can operate in a networked environment using logicalconnections via wired and/or wireless communications to one or moreremote computers, cellular based devices, user equipment, smartphones,or other computing devices, such as workstations, server computers,routers, personal computers, portable computers, microprocessor-basedentertainment appliances, peer devices or other common network nodes,etc. The computer 1112 can connect to other devices/networks by way ofantenna, port, network interface adaptor, wireless access point, modem,and/or the like.

The computer 1112 is operable to communicate with any wireless devicesor entities operatively disposed in wireless communication, e.g., aprinter, scanner, desktop and/or portable computer, portable dataassistant, communications satellite, user equipment, cellular basedevice, smartphone, any piece of equipment or location associated with awirelessly detectable tag (e.g., scanner, a kiosk, news stand,restroom), and telephone. This comprises at least Wi-Fi and Bluetoothwireless technologies. Thus, the communication can be a predefinedstructure as with a conventional network or simply an ad hoccommunication between at least two devices.

Wi-Fi allows connection to the Internet from a desired location (e.g., avehicle, couch at home, a bed in a hotel room, or a conference room atwork, etc.) without wires. Wi-Fi is a wireless technology similar tothat used in a cell phone that enables such devices, e.g., mobilephones, computers, etc., to send and receive data indoors and out,anywhere within the range of a base station. Wi-Fi networks use radiotechnologies called IEEE 802.11 (a, b, g, etc.) to provide secure,reliable, fast wireless connectivity. A Wi-Fi network can be used toconnect communication devices (e.g., mobile phones, computers, etc.) toeach other, to the Internet, and to wired networks (which use IEEE 802.3or Ethernet). Wi-Fi networks operate in the unlicensed 2.4 and 5 GHzradio bands, at an 11 Mbps (802.11a) or 54 Mbps (802.11b) data rate, forexample, or with products that contain both bands (dual band), so thenetworks can provide real-world performance similar to the basic 10BaseTwired Ethernet networks used in many offices.

The above description of illustrated embodiments of the subjectdisclosure, including what is described in the Abstract, is not intendedto be exhaustive or to limit the disclosed embodiments to the preciseforms disclosed. While specific embodiments and examples are describedherein for illustrative purposes, various modifications are possiblethat are considered within the scope of such embodiments and examples,as those skilled in the relevant art can recognize.

In this regard, while the disclosed subject matter has been described inconnection with various embodiments and corresponding Figures, whereapplicable, it is to be understood that other similar embodiments can beused or modifications and additions can be made to the describedembodiments for performing the same, similar, alternative, or substitutefunction of the disclosed subject matter without deviating therefrom.Therefore, the disclosed subject matter should not be limited to anysingle embodiment described herein, but rather should be construed inbreadth and scope in accordance with the appended claims below.

What is claimed is:
 1. A micro-electro-mechanical system (MEMS)gyroscope, comprising: a drive oscillation component configured tovibrate a sensor mass at a drive resonance frequency; a sense circuitconfigured to: detect a deflection of the sensor mass; and generate,based on the deflection and the drive resonance frequency, a demodulatedoutput; and a signal processing component configured to: receive a setof frequencies comprising a first value representing the drive resonancefrequency, a second value corresponding to a sense resonance frequencyassociated with the sense circuit, and tone values representing tones ofthe drive resonance frequency, and apply, based on the first value thesecond value, and the tone values, a notch filter to the demodulatedoutput to obtain a filtered output.
 2. The MEMS gyroscope of claim 1,wherein the drive resonance frequency corresponds to a resonantfrequency of the sensor mass.
 3. The MEMS gyroscope of claim 2, whereinthe drive oscillation component is further configured to generatemechanical resonance of the sensor mass at the drive resonancefrequency.
 4. The MEMS gyroscope of claim 1, wherein the sense circuitis further configured to detect a displacement of the sensor masscorresponding to a coriolis force.
 5. The MEMS gyroscope of claim 4,wherein the sense circuit is further configured to determine a change incapacitance of a sensor that has been capacitively coupled to the sensormass.
 6. The MEMS gyroscope of claim 5, wherein the sense circuit isfurther configured to: generate, based on the change in capacitance, adeflection output; amplify the deflection output using acharge-to-voltage amplifier to obtain an amplified output; anddemodulate, based on the drive resonance frequency, the amplified outputto obtain the demodulated output.
 7. The MEMS gyroscope of claim 1,wherein the sense circuit is further configured to: convert thedemodulated output to a digital value utilizing an analog-to-digitalconverter.
 8. The MEMS gyroscope of claim 7, wherein the signalprocessing component is further configured to apply the notch filter tothe digital value to obtain the filtered output.
 9. The MEMS gyroscopeof claim 1, wherein the signal processing component is furtherconfigured to apply a low pass filter to the filtered output.
 10. Amethod, comprising: vibrating, by a drive oscillation component of amicro-electro-mechanical system (MEMS) gyroscope, a sensor mass of theMEMS gyroscope at a drive resonance frequency; detecting, by a sensecircuit of the MEMS gyroscope, a deflection of the sensor mass;generating, by the sense circuit based on the deflection and the driveresonance frequency, a demodulated output; and in response to receiving,by a signal processing component of the MEMS gyroscope, a set offrequencies from a system, the set of frequencies comprising a firstvalue representing the drive resonance frequency a second valuecorresponding to a sense resonance frequency associated with the sensecircuit, and a group of values representing integer multiples of thedrive resonance frequency, applying, by the signal processing componentbased on the first value, the second value, and the group of values, anotch filter to the demodulated output to obtain a filtered output. 11.The method of claim 10, wherein the drive resonance frequencycorresponds to a resonant frequency of the sensor mass.
 12. The methodof claim 11, wherein the vibrating of the sensor mass comprisesgenerating, by the drive oscillation component, mechanical resonance ofthe sensor mass at the drive resonance frequency.
 13. The method ofclaim 10, wherein the detecting of the deflection comprises detecting,by the sense circuit, a displacement of the sensor mass corresponding toa coriolis force.
 14. The method of claim 13, wherein the detecting ofthe displacement comprises determining a change in capacitance of asensor that is capacitively coupled to the sensor mass.
 15. The methodof claim 14, wherein the generating of the demodulated output comprises:amplifying a deflection output representing the change in capacitanceusing a charge-to-voltage amplifier to obtain an amplified output; anddemodulating, based on the drive resonance frequency, the amplifiedoutput to obtain the demodulated output.
 16. The method of claim 10,wherein the generating of the demodulated output comprises convertingthe demodulated output to a digital value utilizing an analog-to-digitalconverter.
 17. The method of claim 16 wherein the applying of the notchfilter comprises applying the notch filter to the digital value toobtain the filtered output.
 18. The method of claim 10, furthercomprising: applying, by the signal processing component, a low passfilter to the filtered output.
 19. A system, comprising: a frequencyidentification component configured to: determine a drive resonancefrequency corresponding to a vibration of a sensor mass of a MEMSgyroscope; and determine a sense resonance frequency of a sense circuitof the MEMS gyroscope; and a programming component configured to: storethe drive resonance frequency a value corresponding to the senseresonance frequency, and tones of the drive resonance frequency in amemory to facilitate an application, by the MEMS gyroscope using thedrive resonance frequency, the value corresponding to the senseresonance frequency, and the tones of the drive resonance frequency, ofa notch filter to a demodulated output corresponding to a coriolis forceassociated with a deflection of the sensor mass of the MEMS gyroscope.20. The system of claim 19, wherein the value represents at least one ofthe sense resonance frequency or a difference between the senseresonance frequency and the drive resonance frequency.
 21. The system ofclaim 19, wherein the frequency identification component is furtherconfigured to: determine drive resonance frequencies corresponding tosensor masses of respective axes of the MEMS gyroscope, wherein thedrive resonance frequencies comprise the drive resonance frequency, andwherein the sensor masses comprise the sensor mass; and determine senseresonance frequencies of sensors corresponding to the sensor masses,wherein the sense resonance frequencies comprise the sense resonancefrequency, and wherein the sense circuit comprises the sensors.
 22. Thesystem of claim 21, wherein the programming component is furtherconfigured to: store the drive resonance frequencies and valuescorresponding to the sense resonance frequencies in the memory tofacilitate use, by the MEMS gyroscope, of notch filters according to thedrive resonance frequencies and the values corresponding to the senseresonance frequencies, wherein the values comprises the value, andwherein the notch filters comprise the notch filter.